102 MORPHOLOGY AND EVOLUTION (2) Cameroon Gorilla (Go rilla gorilla — Rufous phase not so restricted ; the red crown is not sharply defined and the body hairs are brownish, with some red hairs intermingled. Occipital region broad, and centre of lambdoid crest blunt. (3) Mountain Gorilla (Gorilla gorilla beringeri Matschie) : — Body stout and stocky. Hair intensely black. Large fleshy callosity on crest on the top of the head. Occipital region very broad and lambdoid crest absolutely flat. As regards other sub-species which have been proposed \G.jacobsi and G. manyema*) Eothschild points out that the material available is too scanty to warrant definite conclusions being drawn. Pocock (80) has summarized our knowledge of the habits of the Anthropoid Apes as follows : — :s The Gibbons are the most expert climbers and bipedal walkers, the least expert quadrupedal walkers. The Orangs rank second in climbing, third in quadrupedal and fourth and last in bipedal activity. The Gorillas take fourth place in climbing, second in bipedal and second in quadrupedal activity. The Chimpanzees stand third in climbing, third in bipedal and first in quadrupedal powers. . . . They have departed least from the primitive form." .From a study of the anatomy of many examples of each Anthropoid, Keith (100) regards the Gorilla as more primitive in many ways than the Chimpanzee. He concludes that the Chimpanzee is a Gorilline derivative in which, with progressive brain development, there have been retrogressive changes in many organs; and * Alix, E., et Bouvier, A. Bull Soc. Zool, France, 1877, pp. 488-490.